Theory and simulation of dynamics in heterogeneous environments
Abstract/Contents
- Abstract
- This thesis develops theoretical methods and simulation approaches to elucidate the dynamics of quantum mechanical processes in heterogeneous condensed phase systems. In the first part of the thesis, we consider non-equilibrium relaxation dynamics. These dynamics play a key role in many problems in chemistry, from exciton transfer in photosynthetic light harvesting to electron transfer in photocatalysis. We use the generalized quantum master equation (GQME) formalism in conjunction with quantum-classical methods to treat nonequilibrium relaxation for systems containing many quantum states, as well as fully atomistic systems. In these systems, we show that the GQME approach is highly accurate while also being more efficient than the same quantum-classical method used directly, sometimes by as much as three orders of magnitude. We present an importance sampling algorithm which efficiently generates the memory kernel of the GQME for systems with many quantum states. We then consider a series of cases where chemically tailoring a heterogeneous environment allows one to control reactivity and dynamics. In particular, we show that simulation can be used to elucidate the role of the environment in driving vibrational relaxation in functionalized self-assembled monolayers on gold. We find that vibrational dynamics measured in experiments on self-assembled monolayers arise from a variety of molecular motions including conformational rearrangement of gauche defects in the monolayer. We also show theoretically how the regioselectivity of a catalyst can be controlled by changing the solvent to enforce ion pairing. We find that mutual polarization of the ion pair and the solvent is a key source of the stabilization of ion-paired transition states that gives rise to selectivity that is observed in experiments. Overall, the theoretical methods and simulations presented allow us to accurately capture and elucidate the dynamics in a variety of heterogeneous condensed phase systems.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2016 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Pfalzgraff, William Clayton |
|---|---|
| Associated with | Stanford University, Department of Chemistry. |
| Primary advisor | Markland, Thomas E |
| Thesis advisor | Markland, Thomas E |
| Thesis advisor | Martinez, Todd J. (Todd Joseph), 1968- |
| Thesis advisor | Subotnik, Joseph |
| Advisor | Martinez, Todd J. (Todd Joseph), 1968- |
| Advisor | Subotnik, Joseph |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | William Clayton Pfalzgraff. |
|---|---|
| Note | Submitted to the Department of Chemistry. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2016. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2016 by William Clayton Pfalzgraff
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